How to Build, Install and Setting Qt Application
Contents
1 Qt Versions
Qt has various versions for various platforms. Each Qt version has its own features and here a list of versions:
| CPU | Qt Version | Display Driver | OpenGL | QtWebEngine | Capacitive Touch | ARM Board |
| S5P4418 | Qt 5.9.1 | EGLFS | Yes | Yes | Multiple-point touch | NanoPi S2/NanoPi M2A/NanoPi Fire2/NanoPC T2/Smart4418 |
| S5P6818 | Qt 5.9.1 | EGLFS | Yes | Yes | Multiple-point touch | NanoPi M3/NanoPi Fire3/NanoPC T3 |
| Allwinner H3 | Qt 4.8.6 | LinuxFB | No | No | Single-point touch | NanoPi-Duo/NanoPi-M1-Plus/NanoPi-M1/NanoPi-NEO-Air/NanoPi-NEO-Core/NanoPi-NEO |
| Allwinner H5 | Qt 4.8.6 | LinuxFB | No | No | Single-point touch | NanoPi-M1-Plus2/NanoPi-NEO-Core2/NanoPi-NEO-Plus2/NanoPi-NEO2 |
| Amlogic S905 | Qt 5.9.1 | LinuxFB | No | No | Single-point touch | NanoPi-K2 |
2 Install Cross Compiler for Qt
(Note: we suggest users use a host PC running a 64-bit Ubuntu 16.04)
Here is a list of cross compilers for various CPUs and ARM boards:
| CPU | Qt Version | Compiler & QtSDK |
| S5P4418 | Qt 5.9.1 | download link |
| S5P6818 | Qt 5.9.1 | download link |
| Allwinner H3 | Qt 4.8.6 | download link |
| Allwinner H5 | Qt 4.8.6 | download link |
| Amlogic S905 | Qt 5.9.1 | download link |
Install a cross compiler by running the following commands:
chmod 755 ./install.sh sudo ./install.sh
3 Cross Compile Qt Program
We took QtE-Demo as an example to show how to compile a Qt program.
3.1 S5P4418 Platform
git clone https://github.com/friendlyarm/QtE-Demo mkdir build && cd build /usr/local/Trolltech/Qt-5.9.1-nexell32/bin/qmake ../QtE-Demo/QtE-Demo.pro make
3.2 S5P6818 Platform
git clone https://github.com/friendlyarm/QtE-Demo mkdir build && cd build /usr/local/Trolltech/Qt-5.9.1-nexell64/bin/qmake ../QtE-Demo/QtE-Demo.pro make
3.3 Allwinner H3 Platform
export PATH=/opt/FriendlyARM/toolschain/4.9.3/bin/:$PATH git clone https://github.com/friendlyarm/QtE-Demo mkdir build && cd build /usr/local/Trolltech/QtEmbedded-4.8.6-arm/bin/qmake ../QtE-Demo/QtE-Demo-Qt4.pro make
3.4 Allwinner H5 Platform
export PATH=/opt/FriendlyARM/toolschain/a64-32bit-tootchain/bin/:$PATH git clone https://github.com/friendlyarm/QtE-Demo mkdir build && cd build /usr/local/Trolltech/QtEmbedded-4.8.6-arm-a64/bin/qmake ../QtE-Demo/QtE-Demo-Qt4.pro make
3.5 Amlogic S905 Platform
export PATH=/opt/FriendlyARM/toolschain/a64-32bit-tootchain/bin/:$PATH git clone https://github.com/friendlyarm/QtE-Demo mkdir build && cd build /usr/local/Trolltech/QtEmbedded-5.9.1-arch64/bin/qmake ../QtE-Demo/QtE-Demo.pro make
4 Run Qt Application on ARM Board
Before you run a Qt application on a board you need to setup the board's environment variables by running the following commands on that board:
For Qt5 run setqt5env:
. /usr/bin/setqt5env
For Qt4 run setqt4env:
. /usr/bin/setqt4env
Run QtE-Demo:
./QtE-Demo -qws
5 Compile Qt Program on ARM Board
We took QtE-Demo as an example to show how to compile a Qt program on an ARM board. Currently this only applies to a S5P4418 or S5P6818 board:
5.1 S5P4418 Platoform
git clone https://github.com/friendlyarm/QtE-Demo mkdir build && cd build /usr/local/Trolltech/Qt-5.9.1-nexell32-armhftools/bin/qmake ../QtE-Demo/QtE-Demo.pro make . setqt5env ./QtE-Demo
5.2 S5P6818 Platform
git clone https://github.com/friendlyarm/QtE-Demo mkdir build && cd build /usr/local/Trolltech/Qt-5.9.1-nexell64-aarch64tools/bin/qmake ../QtE-Demo/QtE-Demo.pro make . setqt5env ./QtE-Demo
6 Auto-Run Qt Application on System Startup
In our test our QtE-Demo application was under the /root directory. Make sure your "/etc/rc.local" file has the following contents:
. /usr/bin/setqt5env /root/QtE-Demo -qws&
If this is a Qt4 system you need to change "setqt5env" to "setqt4env".
7 Display Rotation
Here is a list of methods you can use to rotate your display for various platforms:
| CPU | Qt Version | Display Rotation |
| S5P4418 | Qt 5.9.1 | export ROTATION=-90 . setqt5env ./YourApp Applicable rotation degrees: 0, 90, 180, -90 |
| S5P6818 | Qt 5.9.1 | export ROTATION=-90 . setqt5env ./YourApp Applicable rotation degrees: 0, 90, 180, -90 |
| Allwinner H3 | Qt 4.8.6 | . setqt4env export QWS_DISPLAY='Transformed:Rot90' ./YourApp Applicable rotation degrees: 0, 90, 180, 270 |
| Allwinner H5 | Qt 4.8.6 | . setqt4env export QWS_DISPLAY='Transformed:Rot90' ./YourApp Applicable rotation degrees: 0, 90, 180, 270 |
| Amlogic S905 | Qt 5.9.1 | . setqt5env export QT_QPA_PLATFORM=linuxfb:fb=/dev/fb0:rotation=90 ./YourApp Applicable rotation degrees: 0, 90, 180, 270 |
8 Common Issues
8.1 Compiler Error: ../QtE-Demo/main.cpp:18:21: fatal error: QtWidgets: No such file or directory
Solution: check your Makefile file generated by qmake. Qt5's path should point to sysroot i.e. rootfs-s5p4418 or rootfs-s5p6818. You need to check whether or not this directory exists under /opt. If it doesn't you need to reinstall your sdk.
8.2 Hide Console Cursor
Hide Cursor
sudo echo 0 > /sys/class/graphics/fbcon/cursor_blink
Show Cursor
sudo echo 1 > /sys/class/graphics/fbcon/cursor_blink
8.3 Hide/Show Mouse Cursor
When you run Qt5 EGLFS you can hide or show your mouse's cursor by setting the QT_QPA_EGLFS_HIDECURSOR environmental variable. When this variable is set to 1 the cursor will be hidden when it is set to 0 the cursor will show.
For example after setqt5env is executed run the following command:
export QT_QPA_EGLFS_HIDECURSOR=0
The cursor will show.
8.4 Extend Boot Logo's Display Time
Since Linux kernel by default sets output to a terminal a boot logo will soon be flushed. Sometimes users prefer their logo to stay for much longer time
This can be done by changing kernel configuration and recompiling a kernel:
Device Drivers ---> Graphics support ---> Console display dirver support ---> < > Framebuffer Console support
Disabling "Framebuffer Console support" allows a Logo to stay long enough until a Qt program runs.
9 Update Log
9.1 Dec-5-2017
- Released English version
9.2 Dec-6-2017
- Added Section 5
9.3 Jan-30-2018
- Added Section 8
